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Modeling And Dynamic Stability Of Distributed Generations, Zhixin Miao Aug 2002

Modeling And Dynamic Stability Of Distributed Generations, Zhixin Miao

Graduate Theses, Dissertations, and Problem Reports (ETD)

The objective of this dissertation is to develop dynamic models for distributed generations (DG), to investigate their impacts on dynamic stability of power distribution systems, and to design controllers for DGs to improve the dynamic stability of the integrated power distribution system.;A two-year distributed generation (DG) project at West Virginia University (WVU) evaluated the impact of various DG sources on actual distribution systems by performing computer simulations. The data is supplied by two regional electric utilities of two actual distribution systems each. In this project several important issues were investigated, including the availability of simulation tools and impacts of DGs …

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Design And Construction Of A Zinc Pot Bearing Material Wear Tester, Ryan Ware Aug 2002

Design And Construction Of A Zinc Pot Bearing Material Wear Tester, Ryan Ware

Graduate Theses, Dissertations, and Problem Reports (ETD)

There are more than fifty galvanizing lines in the U.S.A. producing galvanized steel sheet by the method of pulling a steel sheet over a roller that is submerged in a liquid zinc bath. Although highly competitive, this product is very lucrative for the Steel Industry. The objective of this research is to assist the U.S. Steel Industry in becoming more competitive with foreign imports by reducing line stoppage for bearing replacement, which currently might be as long as one week to a month.;A great variety of wear and corrosion resistant zinc-pot bottom roller bearing metals and ceramics have already been …

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Advanced Generation Niosh Automatically Deployable Rollover Protective Structure (Autorops), Khaled Ali Alkhaledi Aug 2002

Advanced Generation Niosh Automatically Deployable Rollover Protective Structure (Autorops), Khaled Ali Alkhaledi

Graduate Theses, Dissertations, and Problem Reports (ETD)

AutoROPS have been developed recently under the sponsorship of the National Institute for Occupational Safety and Health (NIOSH) in collaboration with the Mechanical and Aerospace Engineering Department at West Virginia University. Unfortunately, numerous tractors' operators have removed the factory ROPS from the Tractors because of the lack of housing area on the tractor, which may result in frequent collision between the ROPS and low-hanging tree branches.;One main purpose of this work was to study the base of the second generation AutoROPS, to insure that the base can withstand the impact loads associated with the rollover of any farm tractor. Another …

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Fine Particle Flotation For Florida Dolomitic Phosphate Pebbles, Zhengxing Gu Aug 2002

Fine Particle Flotation For Florida Dolomitic Phosphate Pebbles, Zhengxing Gu

Graduate Theses, Dissertations, and Problem Reports (ETD)

A Florida dolomitic phosphate pebble sample was processed using a 1.2 liter stirrer-tank flotation cell and 2-in ID packed flotation column aiming at achieving a phosphate concentrate containing more than 30% P2O 5 and less than 1.0% MgO contents at high P2O5 recovery.;The characteristics of fatty acid collector, FA-12 and a newly developed PA-31 collector were evaluated for frothability and dolomite flotation rate. The evaluation results show that both reagents have high frothability, but PA-31 has much stronger frothability than FA-12, and higher selectivity in separating dolomite from phosphate mineral.;The mineralogical study indicates that the phosphate pebble sample needs to …

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Ant Colony Heuristics For The Dynamic Facility Layout Problem, Jin Shang Aug 2002

Ant Colony Heuristics For The Dynamic Facility Layout Problem, Jin Shang

Graduate Theses, Dissertations, and Problem Reports (ETD)

As global economic competition and cooperation become more and more drastic, the enterprise's facility layout needs to be more flexible to adapt to the rapidly changing environment. Therefore, attention should be given to the dynamical nature of the facility layout. In other words, the flow of materials between departments changes during the planning horizon (multiple periods) and should be considered. This problem is known as the dynamic facility layout problem (DFLP).;This research proposes three heuristics based on the ant colony optimization (ACO) heuristic to solve the DFLP. The performance of the heuristics was evaluated using two data sets taken from …

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Phase Equilibrium Study Of Methane Hydrate, Rahul Shukla Aug 2002

Phase Equilibrium Study Of Methane Hydrate, Rahul Shukla

Graduate Theses, Dissertations, and Problem Reports (ETD)

Gas hydrates are solid metastable ice like compounds formed when gas comes in contact with water and have the ability to form at low temperatures. In this study, methane gas hydrates were formed in a Berea sandstone core, which was saturated with brine and then pressurized with methane gas. The formation temperatures were 34°F, 36°F and 40°F and the initial pressures were in the range of 1000--1200 psi. Variation of the methane pressure was monitored with time during the formation run. Dissociation experiments were then carried out and the pressure profile along the core with time was recorded. The volume …

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Monitoring Process And Assessing Uncertainty For Anfis Time Series Forecasting, Yan K. Cathey Deng Aug 2002

Monitoring Process And Assessing Uncertainty For Anfis Time Series Forecasting, Yan K. Cathey Deng

Graduate Theses, Dissertations, and Problem Reports (ETD)

Although intelligent tools such as neural network, fuzzy logic and neuro-fuzzy methods have been applied in time series forecasting for some time, problems of monitoring forecasting processes and assessing uncertainty for the forecasts represent a major challenge that need to be fully investigated. In this research, we use statistical methods to analyze nonstationary time series forecasting where forecasts are accrued from a neuro-fuzzy ANFIS model. The main focus is to monitor the process and assess the uncertainty of the forecasts.;Single-step-ahead forecasts and multiple-step-ahead forecasts have been investigated by using three nonstationary time series data sets. It is shown that the …

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Experimental Characterization Of The Mechanical Consequences Of A Debonded Total Hip Stem With An Unsupported Distal Tip, Keith Thomas Hustosky Aug 2002

Experimental Characterization Of The Mechanical Consequences Of A Debonded Total Hip Stem With An Unsupported Distal Tip, Keith Thomas Hustosky

Graduate Theses, Dissertations, and Problem Reports (ETD)

Cemented total hip arthroplasty (THA) has enjoyed widespread success since its introduction over thirty years ago. Despite the successes, there are threats to the long term stability of THA, chief among them aseptic loosening of the femoral stem. Femoral component loosening is a significant problem because it prevents the efficient transfer of hip joint forces through the cement to the proximal femur. This may cause pain in the patient severe enough to warrant surgery to replace the loose component.;The predominant approach to preventing loosening of cemented THA femoral components focuses on improving the bond between the prosthesis stem and the …

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Students' Attitudes, Knowledge, And Commitment To Implementation Of Multicultural Education In A Teacher Education Program, Pei Jian Zhou Aug 2002

Students' Attitudes, Knowledge, And Commitment To Implementation Of Multicultural Education In A Teacher Education Program, Pei Jian Zhou

Graduate Theses, Dissertations, and Problem Reports (ETD)

In recent years, there are more research studies in the field of teacher education. These research studies examine the effects of multicultural education initiatives on the change of students' attitudes and perspectives on multicultural education in teacher education programs. The results of there research studies have revealed that further studies are called for in this area of study, because the results of the previous studies are not always positive and clear. The purpose of this study is to see if there is any attitude change during the program, how the five-year teacher education program enhances the pre-service teacher education experience …

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Long-Term Creep Of Encased Polymer Liners, Shalini Rangarajan Aug 2002

Long-Term Creep Of Encased Polymer Liners, Shalini Rangarajan

Graduate Theses, Dissertations, and Problem Reports (ETD)

Due to increasing costs and inconveniences in replacing deteriorated sewer pipelines by conventional excavation methods, the trenchless or 'no-dig' technology is being extensively used. In trenchless technology, a polymer or reinforced polymer is applied to the inside of the deteriorated host pipe to prevent ground water from seeping into the sewer pipelines. In this work, a testing method was developed to determine the long-term creep behavior of encased polymer liners.;Short-term tests, following the ASTM D790 procedure, were conducted on pipe liner samples to determine the initial elastic modulus and compare it to the elastic modulus obtained from long-term testing of …

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Uncertainty Assessment For Cfd Using Error Transport Equation, Gusheng Hu Aug 2002

Uncertainty Assessment For Cfd Using Error Transport Equation, Gusheng Hu

Graduate Theses, Dissertations, and Problem Reports (ETD)

While Computational Fluid Dynamics (CFD) is making extensive use of the power of computational technology, it is also facing a serious problem arising from the so-called numerical uncertainty. The overall uncertainty (or the global error) involved in CFD results can be due to different sources mainly contributed by (i) discretization error (or solution error due to incomplete grid convergence), (ii) iteration convergence error, (iii) grid generation errors (skewness, grid aspect and expansion ratio, coordinate transformation etc.), and (iv) round-off errors. In this study an in-depth discussion concerning these issues is presented with an emphasis on the discretization error in regard …

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Experimental Study Of Thermosiphon Performance, Sumeeth S. Sivanagere Aug 2002

Experimental Study Of Thermosiphon Performance, Sumeeth S. Sivanagere

Graduate Theses, Dissertations, and Problem Reports (ETD)

A model single phase loop thermosiphon was designed and built such that velocity profiles and heat transfer rates could be studied by obtaining temperature data, along with a detailed set of non-intrusive Laser Doppler Velocimetry measurements. The quantities measured were the instantaneous velocity profiles for the water flow. These velocities were then reduced into sets of mean and root mean square velocities, for different angles of tilt of the experimental setup. Nominal heating and cooling rates were held constant.;The single phase thermosiphon consisted of an aluminum flow loop, fitted with a test section made of Plexiglas, that was rectangular in …

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Seepage In Earth Slopes With Longitudinal Drainage Trenches, Ricardo Constantino Kiriakidis L. Aug 2002

Seepage In Earth Slopes With Longitudinal Drainage Trenches, Ricardo Constantino Kiriakidis L.

Graduate Theses, Dissertations, and Problem Reports (ETD)

The major objective of this study was to determine the effect of hydraulic conductivity on the effectiveness and efficiency of longitudinal drains and on the time to reach steady state seepage under controlled laboratory conditions. An apparatus capable of simulating different slope angles and trench spacing was utilized in this study. By using this apparatus it was possible to obtain data regarding flow pattern, pressure heads, saturation time, influence of slope angle (theta), the trench spacing (W = 2w) and seepage depth (h) under steady state and transient conditions for different values of hydraulic conductivity. Two different soil types with …

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Study Of Natural Gas Vehicles (Ngv) During The Fast Fill Process, Eric Paul Shipley Aug 2002

Study Of Natural Gas Vehicles (Ngv) During The Fast Fill Process, Eric Paul Shipley

Graduate Theses, Dissertations, and Problem Reports (ETD)

Natural gas is being used as an alternative fuel to gasoline. Natural gas vehicle (NGV) refueling stations, however, are not able to guarantee a 100% full fill to NGV's. A system was designed and built to better understand the characteristics of CNG during the fill process. Useful characteristics of CNG during the fill process are temperature, pressure, and flow rate, as well as, total volume dispensed. CNG is dispensed to an NGV through a process known as the fast fill process, since it is completed in less than five minutes. The system that was built is transportable, which means that …

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Aging Model For Commercial Polymers, Kevin J. Ford Aug 2002

Aging Model For Commercial Polymers, Kevin J. Ford

Graduate Theses, Dissertations, and Problem Reports (ETD)

Physical aging of polyvinyl chloride, high-density polyethylene, and polyester reinforced with polyester fibers specimens have been investigated. These materials are commercially available and are currently used in trenchless relining of sewer pipes. The analysis uses the effective-time theory and time-temperature superposition (TTSP) methods proposed by Struik, as well as variations of these methods, as proposed by Chai and McCrum, Guerdoux et al. and others. The creep data generated by this study show that the time-dependent creep properties of these materials can be modeled within experimental error with slight changes to the above methods. To predict the creep behavior of full-scale …

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Gamma Prime Precipitation Modeling And Strength Responses In Powder Metallurgy Superalloys, Jian Mao Aug 2002

Gamma Prime Precipitation Modeling And Strength Responses In Powder Metallurgy Superalloys, Jian Mao

Graduate Theses, Dissertations, and Problem Reports (ETD)

Precipitation-hardened nickel-based superalloys have been widely used as high temperature structural materials in gas turbine engine applications for more than 50 years. Powder metallurgy (P/M) technology was introduced as an innovative manufacturing process to overcome severe segregation and poor workability of alloys with high alloying contents. The excellent mechanical properties of P/M superalloys also depend upon the characteristic microstructures, including grain size and size distribution of gamma' precipitates. Heat treatment is the most critical processing step that has ultimate influences on the microstructure, and hence, on the mechanical properties of the materials. The main objective of this research was to …

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Stress Response Genes In The Human Proximal Tubules, Doyeob Kim Aug 2002

Stress Response Genes In The Human Proximal Tubules, Doyeob Kim

Graduate Theses, Dissertations, and Problem Reports (ETD)

The heat shock proteins (hsps) are believed to provide protection against a variety of insults such as elevated temperature, heavy metals and chemical agents. The goal of this study was to determine if the immortalized HK-2 human proximal tubule cell line could provide a model system to study the stress response of the proximal tubule cell. Heat stress, elevated temperature at 42.5°C for 1 hr, caused a marked increase only in hsp 70 mRNA and protein, but not that of hsp 27 or hsp 60 mRNA and protein. Similar results were obtained when the cells were subjected to 100 muM …

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Overwintering Abundance And Distribution Of Striped Bass (Morone Saxtilis) In The Hudson River Estuary Using Hydroacoustic Techniques, Brian William Nagy May 2002

Overwintering Abundance And Distribution Of Striped Bass (Morone Saxtilis) In The Hudson River Estuary Using Hydroacoustic Techniques, Brian William Nagy

Graduate Theses, Dissertations, and Problem Reports (ETD)

Using a modification of standard techniques, a target strength to length relationship was developed for white perch (Morone americana) and striped bass (Morone saxtilis). This target strength to length relationship was compared to two standard relationships (Love and Foote). The calculated relationship was not found to be significantly different from Love's equation, but was different from Foote's equation. This calculated relationship was applied to hydroacoustic data collected on the Hudson River in December of 1995 and 1997. The goal of the hydroacoustic data collection was to assess the abundance and distribution of overwintering Hudson River striped bass. Results from this …

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Modulation Of Thiols And Pulmonary Immune Responses Due To Diesel Exhaust Particle (Dep) Exposure, Nabil Hussain Al-Humadi May 2002

Modulation Of Thiols And Pulmonary Immune Responses Due To Diesel Exhaust Particle (Dep) Exposure, Nabil Hussain Al-Humadi

Graduate Theses, Dissertations, and Problem Reports (ETD)

Environmental exposure to diesel exhaust particles (DEP) has been of concern because of its potential contribution to the increased prevalence of acute and chronic airway diseases. The objective of this study was to investigate the role of thiol changes (due to DEP exposure) in immune responses. Rats were exposed to OVA, DEP, or both by intratracheal instillation (IT) and/or inhalation. IT-DEP exposure significantly increased the inflammatory parameters and thiol levels in both Sprague-Dawley and Brown Norway rats. Exposure to DEP and/or OVA resulted in significant increases in neutrophils, LDH, total protein, and albumin content in lavage fluid. Alveolar macrophage (AM) …

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Integrated Through -Wafer Optical Monitoring Of Mems For Closed -Loop Control, Jeremy Michael Dawson May 2002

Integrated Through -Wafer Optical Monitoring Of Mems For Closed -Loop Control, Jeremy Michael Dawson

Graduate Theses, Dissertations, and Problem Reports (ETD)

Current trends in many microelectronic systems show an increased use of microelectromechanical systems (MEMS) to perform a variety of tasks. The increased market for MEMS has led to microsystem technologies being employed in physically demanding environments and safety critical applications. This creates the need for higher degrees of certainty in MEMS operation, especially in systems that contain drive components operating under time varying load conditions. Situations such as these give rise to the need for detailed knowledge of the operational states of MEMS over the lifetime of the device, as well as device fault detection. Accurately obtaining this information by …

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Small Mammal Communities On A Reclaimed Mountaintop Mine/Valley Fill Landscape In Southern West Virginia, Howard Douglas Chamblin May 2002

Small Mammal Communities On A Reclaimed Mountaintop Mine/Valley Fill Landscape In Southern West Virginia, Howard Douglas Chamblin

Graduate Theses, Dissertations, and Problem Reports (ETD)

Mountaintop mine/valley fill is a large-scale form of strip mining whose effects on small mammals had not previously been examined. Small mammals were captured by Sherman trap and drift fence array (pitfall and funnel traps) on 3 treatments representing the mined landscape and intact forests representing the unmined condition. Peromyscus ( P. leucopus and maniculatus) dominated Sherman captures and were the most common array capture. Eastern chipmunks (Tamias striatus), woodland jumping mice (Napaeozapius insignus), woodland voles (Microtus pinetorum), northern short-tailed shrews (Blarina brevicauda), and pygmy shrews (Sorex hoyi) were more common in forest treatments; Peromyscus, house mice (Mus musculus), southern …

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Analysis And Robust Decentralized Control Of Power Systems Using Facts Devices, Karl E. Schoder May 2002

Analysis And Robust Decentralized Control Of Power Systems Using Facts Devices, Karl E. Schoder

Graduate Theses, Dissertations, and Problem Reports (ETD)

Today's changing electric power systems create a growing need for flexible, reliable, fast responding, and accurate answers to questions of analysis, simulation, and design in the fields of electric power generation, transmission, distribution, and consumption. The Flexible Alternating Current Transmission Systems (FACTS) technology program utilizes power electronics components to replace conventional mechanical elements yielding increased flexibility in controlling the electric power system. Benefits include decreased response times and improved overall dynamic system behavior. FACTS devices allow the design of new control strategies, e.g., independent control of active and reactive power flows, which were not realizable a decade ago. However, FACTS …

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Use Of West Virginia Permanent Traffic Recorder Data To Develop Factors For Traffic And Truck Variation, Jacob Scott D'Angelo May 2002

Use Of West Virginia Permanent Traffic Recorder Data To Develop Factors For Traffic And Truck Variation, Jacob Scott D'Angelo

Graduate Theses, Dissertations, and Problem Reports (ETD)

The purpose of this study was to use data collected from the 52 permanent count stations located throughout the state to develop four sets of factors that would assist the West Virginia Department of Transportation (WVDOT) in the management and engineering of the roadways in West Virginia.;The objectives of this study were to: (1) Establish correction factors that can be applied to the short-term single pneumatic tube traffic count stations to adjust for the effect of three or more axle trucks on the volume counts. (2) Establish factors that use the peak hour volume (PHV) to estimate the design hour …

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In Vitro Genotoxicity Investigations Of Jet Fuel, Shawna M. Jackman May 2002

In Vitro Genotoxicity Investigations Of Jet Fuel, Shawna M. Jackman

Graduate Theses, Dissertations, and Problem Reports (ETD)

The 60 billion gallons of jet propulsion fuels consumed worldwide create an exposure situation to over two million military and civilian personnel per year. The potential mutagenic, genotoxic and cytotoxic potency of military jet fuel was investigated in this study through in vitro systems such as human peripheral lymphocytes and metabolically competent hepatic cell lines. A battery of genotoxicological evaluations is employed, focusing on the comet assay to examine the induction of DNA damage. Cellular exposures to fuel were carried out directly and indirectly with an ethanol (EtOH) carrier. The fuel was found to be nonmutagenic with and without metabolic …

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Use Of Flowable Fill As A Backfill Material Around Buried Pipes, Andrew Ray Simmons May 2002

Use Of Flowable Fill As A Backfill Material Around Buried Pipes, Andrew Ray Simmons

Graduate Theses, Dissertations, and Problem Reports (ETD)

The objective of this research work was to study the performance of flowable fill as a backfill material around buried plastic corrugated pipes. The flowable fill materials used in this study contained varying proportions of fly ash, bottom ash, river sand, waste foundry sand, and cement. The relationships between flowability and compressive strength were investigated for different mixtures by using ASTM test methods in order to design suitable mixtures that meet WVDOT materials specifications. The second phase of the research was to design and construct a laboratory-scale pipe testing apparatus. The final phase was to find the pipe-soil interactions under …

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Nondestructive Evaluation Of Frp Composite Members Using Infrared Thermography, Gurudutt Sundara Ram Bangalore May 2002

Nondestructive Evaluation Of Frp Composite Members Using Infrared Thermography, Gurudutt Sundara Ram Bangalore

Graduate Theses, Dissertations, and Problem Reports (ETD)

The objective of this research is to establish infrared thermography as an effective tool for nondestructive evaluation of structural members made of fiber reinforced polymer (FRP) composite materials. The applicability of this method for the detection of subsurface anomalies such as voids, cracks, debonding, and delaminations in concrete bridge decks and pavements and in some configurations of FRP decks has been studied earlier by other researchers. These earlier studies have yielded reasonably satisfactory results though further refinement of the methodology and improvements in the image processing techniques were recommended.;To enhance the effectiveness of the infrared thermography technique, it is important …

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Modeling The Pultrusion Process To Obtain Low Void Fraction Composites, Adam Douglas Freed May 2002

Modeling The Pultrusion Process To Obtain Low Void Fraction Composites, Adam Douglas Freed

Graduate Theses, Dissertations, and Problem Reports (ETD)

This work was directed at improving the strength and durability of pultruded composites. Pultruded composites are being used in an increasingly wider range of applications, and, as a result, a higher demand has been placed on the performance capabilities of the various components.;One target area for improving composites is the fraction of voids in the final product. The presence of voids in a composite decreases the Interlaminar Shear Strength, provides a site for the formation of fractures, and increases the susceptibility of the part to outside contaminants.;In this work, the various steps of the pultrusion process are analyzed in order …

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Nucleation And Coagulation Of Particulate Matter Inside A Turbulent Exhaust Plume Of A Diesel Vehicle, Donghee Kim May 2002

Nucleation And Coagulation Of Particulate Matter Inside A Turbulent Exhaust Plume Of A Diesel Vehicle, Donghee Kim

Graduate Theses, Dissertations, and Problem Reports (ETD)

The objective of this study is to develop a physical model to accurately predict the nucleation, coagulation, and dynamics of particulate matter emission from diesel-fueled engines. The uniqueness of this research is that measured particulate matter (PM) size distribution data is not required a priori to solve the nucleation/coagulation equations; instead the PM concentration is predicted based on the fuel sulfur content, fuel to air ratio, exhaust flow rate, and the ambient conditions. This study presents the CFD modeling of an exhaust plume dispersed from a stack pipe of a tractor truck powered by a 330 HP diesel engine. This …

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Establishing Design Vehicles For The Hang-Up Problem, Amy Lorraine Clawson May 2002

Establishing Design Vehicles For The Hang-Up Problem, Amy Lorraine Clawson

Graduate Theses, Dissertations, and Problem Reports (ETD)

Current design vehicles do not address the hang-up problem. Two factors affect hang-ups: vehicle geometry and roadway geometry. There is a need to establish design vehicle characteristics for hang-up prone vehicles to reduce hang-ups potential.;Roadway geometry and vehicle characteristics relative to the hang-up problem were reviewed. Consideration of these properties by key organizations and associations, and government regulations were studied, and research performed by individuals establishing other design vehicles were analyzed. A general methodology was established.;When choosing design vehicles for the vehicle population, variation in vehicle population, the ramifications of using a limited number of vehicles, and local conditions were …

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Efficiency Of Shear-Induced Agglomeration Of Particulate Suspensions Subjected To Bridging Flocculation, Sushant Agarwal May 2002

Efficiency Of Shear-Induced Agglomeration Of Particulate Suspensions Subjected To Bridging Flocculation, Sushant Agarwal

Graduate Theses, Dissertations, and Problem Reports (ETD)

This study examines the problem of shear-induced agglomeration of particles such as fillers and pigments in polymer solutions, where polymer molecules adsorb on the surface of particles and form a bridge between them causing agglomeration. The rate of agglomeration is usually obtained by multiplying the rate of collision of particles by the collision efficiency. In a laminar flow field, the collision frequency is readily given by Smoluchowski's expression. If agglomeration takes place by coagulation, the collision efficiency is well studied and the influences of hydrodynamic and colloidal forces are well understood. In case of polymer bridging, the collision efficiency is …

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